Periodic puzzle



FIG. 1 is a top plan view of the periodic puzzle showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a side view thereof;

FIG. 4 is a top and rear perspective view showing the rows of periodic indicia in an alternate position within the puzzle; and,

FIG. 5 is a top and front perspective view of FIG. 4. 

The ornamental design for the periodic puzzle, as shown and described. 